This project is simple and should be solved by this powerful software.
I searched a lot to solve this problem, but I did not get any results.
This project is important to me.
Help me please. I do not know where the problem can be?

I can help you with getting the various analysis tools the solvers offer to run, but you need to analyze the output and modify the model yourself. There are three ways of analyzing infeasibilities that I find helpful:

1) Since you are convinced that the model has a feasible point, provide it in the variable attribute .l (x.l = ... before the solve, turn the equation listing all on (option limrow=1e9;) and solve. Check the equation listing for INFES in the equation listing to see where your "feasible" solution is actually infeasible.

2) Automatic relaxation. You can find a minimal relaxation of your infeasible model by allowing bounds and constraints to be violated. You can give different weights to the bounds and constraints and even do not allow to violate some bounds and constraint. This all can be accomplished by adding slack variables to your model and the slacks into the objective with different weights. Some solver, like Cplex, have an option to do this automatically (see https://www.gams.com/latest/docs/S_CPLE ... RELAXATION).

3) Use the conflict refiner (suggested by the previous answer). Just supply the "iis yes" in an option file and look at the listing file to get the smallest set of constraints and bounds that make the problem infeasible. In your case the set is rather larger and hence the tool is not that useful.